Mixing machine or the like



Dec. 15, 1931. H BANBURY 1,836,355

MIXING MACHINE OR THE LIKE Filed March 3, 1928 INVENTOR www Bg AZ'immys,

Patented Dec. 15, 1931 UNITED STATES PATENT OFFICE -FERNLEY I-I. BANBURY, OF ANSONIA, CONNECTICUT, ASSIGNOR TO FARREL-BIRMING- CONNECTICUT MIXING MACHINE OR THE LIKE Application filed March 3,

This invention relates to mixing machines, and aims to provide certain improvements therein. 7

The invention, while applicable to other 71 devices, is particularly directed to mixing machines for rubber compositions, and finds one of its most efficient applications in the case of the well-known Banbury mixer,

which is designed primarily for thoroughly action.

mixing or kneading raw rubber with the other constituents which go to make up commercial mixtures.

In this type of machine especially there are e one or more rotors which operate in a partially circular trough, the rotor being so shaped on its advancing face as to smear the mix against the wall of the trough. In this type of machine particularly, there is very severe outward pressure on the trough wall which results in a considerable amount of wear on the wall. There is also a very strong tendency to rotate the trough wall due to the resistance of the material to the smearing The heat generated in the mix is quite excessive, and in order to keep the temperature within proper limitations, it has been customary to water-jacket the trough wall and pass a copious supply of water through the jacket.

The particular machines inquestion are of massive construction and necessarily expensive, and the wear on the trough wall eventually reduces the machine to a condition of 36. inefliciency, with the efiect that the entire machine or a large part thereof must be discarded;

According to the present invention, I aim to improve the construction of such machines or machines involving similar conditions, and 40' 1928. Serial No. 258,885.

face practically restores the machine to its original eficiency at an expense which is very much less than the cost of a new machine. I

My invention also includes certain other important features of novelty which will be hereinafter more fully described.

Referring to the drawings, which illustrate several forms of the invention,

Figure 1 is a transverse section of the preferred form of the invention as applied to a. standard two-rotor Banbury mixer.

Fig. 2 is a longitudinal section taken on the line 22 of Fig. l, the rotor being shown as broken away.

Fig. 3 is a sectional view of a detail.

Fig. 4 is a sectional view of a modified form.

Fig. 5 is a detail.

Referring to the drawings, let A indicate a mixer of the Banbury construction, which in the illustration comprises two rotors B and G rotating respectively in the direction of the arrows, these rotors being operative in partly circular chambers or troughs D and E, respectively. F indicates a feed passage, the walls G of which are continued downwardly, being joined to the walls H and I of the troughs D and E, respectively. Between the troughs is arranged a sliding valve J, which when moved longitudinally, creates a discharge opening for the troughs. Except for the movable valve or gate, in the construction heretofore adopted for such mixers a single body casting has been used, the walls G, H and I being constructed integrally. Mixers of this type have also been constructed in which but a single-rotor is used, working in a single trough. In either case, as before stated, the wear on the trough walls has been excessive, and the customary method of reducing it has been to harden.

the walls as much as possible.

According to the present invention, I provide separable walls for the trough or troughs whereby, when the wear has progressed to a certain extent, the wall may be removed and replaced by a new wall. To this end, in; the preferred form of the invention the machine is preferably constructed with separable end walls K, L (Fig. 2), and these end walls are provided with recesses or slots M, N, which are adapted to receive the ends of the separable walls, it being understood that the slots extend only so far as the side edges of the walls, so that the ends of the slots tend to prevent angular movement of the walls by engaging the side edges of the walls. By preference, the total length of the wall is less than the extreme distance between the bottoms of the opposite slots, so that expansion of the wall is permitted, such expansion taking place because of the heat conditions which arise during operation. Nevertheless, the ends of the walls extend into the recesses or slots to such an extent that even under extreme conditions of contraction the wall will not leave the slots.

In the operation of such machines there is a strong tendency for the rotors to axially turn the walls in the direction of rotation of the rotors. My invention preferably provides an additional means for resisting this tendency to turn, and in the preferred construction such. means comprise flanges O, which, by preference, run the entire length of the walls, each of such flanges being enaged by a flange Q formed upon the plate II, which may be either separate from or integral with the base of the device. The two flanges may be bolted together, although this is not ordinarily necessary since when the machine is normally operating there is no tendency for the trough to rotate except in the direction of the arrows. Occasionally, however,

the machine may be reversed, at which time the bolt will prevent reverse turning of the walls. I may provide a clip Z (Fig. 5) which holds the separable wall against reverse turning, and which also permits its longitudinal expansion. Either construction compels the separable wall to expand away from the valve or gate opening, so that such gate is not interfered with. The flange O is also of considerable utility in avoiding any possible buckling of the lower edge of the trough under the action of the rotor. Any other means may be employed to prevent rotation of the walls, but I prefer those shown, for the reason that they not oni y effectually prevent the rotation in a simple way, but also provide a removable surrace S against which the valve operates, so that if there is any wear at this point, it maybe compensated for.

At the tops of the separable walls there is preferably provided a flange T on the easing which fits with accuracy the separable wall, it being understood that at this point and also in the grooves N there may be located suitable packing means. Ordinarily, however, the joints, if carefully made, will be sufficiently leak-tight. The wall normally is not flush with the feed opening wall, so that when expanded it will not encroach on the feeding opening passage, and thus interfere with the commonly employed float ing weight, which assists in the feeding of the mixture.

As before indicated, machines of this type generate very considerable quantities of heat, and it is necessary to cool the device as well as the mixture being operated upon, the troughs being water-jacketed for this purpose. In the illustration given, the waterjackets are indicated at U. lVhile the waterjacket space may be isolated from the removable trough walls by the provision of an interior wall against which the trough fits tightly, I much prefer to provide a construction in which the separable walls constitute the complete troughs. In carrying the preferred form of the invention into effect, I provide a series of longitudinal members V, V, which extend from end to end of the framework, these members being arranged by preference in the form of a grid so that their inner edges constitute a circular support for the trough walls while between the longitudinal members the trough walls are accessible to the cooling fluid. By this means the fluid is brought into direct contact with the trough walls without the intervention of any air space between the cooled surface and the actual walls themselves. By this construction I am enabled to take up the very severe radial strains which are placed upon the trough walls by the operation of the rotors, while not interfering with the direct transmission of heat to the cooling fluid. The members V may be supported at their ends in any way. I have shown them as being formed as a part of the central casting IV which is either bolted or otherwise united to the end frames K, L. While water may be circulated directly through the chambers U, U, I am enabled by the combination of the structure just described with the system of cooling set forth in my application No. 286,137, filed November 28, 1927, to very much minimize any chance of leakage into the troughs, so that extreme care need not be taken to make and preserve absolute leak-tight joints under all conditions of expansion and contraction where the side portions of the troughs engage the feed and discharge openings. By the invention referred to in said application, the trough walls are cooled by jets indicated at X, X, which spray the cooling fluid directly against the walls. The cooling results by this system are superior to those of the ordinary water-jacket, and any excess of water tending to accumulate in the upper spaces between the members V may be permitted to escape by a series of openings Y through such members. The lower plate R of the casing is preferably inclined upwardly as shown at R in Fig. l, and outlets R are provided for the water below the top of the flange. This construction prevents leakage at the lower part of the cooling chamber. In the preferred construction of the machine, if it is desired to replace one of the troughs it is necessary only to separate one of the end pieces from the frame and pull out the old trough and insert the new. This can be easily done espe cially where the bolts or bolt between the flanges O and Q; are omitted.

It will be understood that the invention is applicable to. single rotor machines as well those employing a plurality of rotors, and it will also be understood that the separable walls may be made sectional, as indicated in Fig. i for instance. While the invention is applicable to other types of machines, it provides the solution of a very serious problem in connection with rubber mixers because of the heavy strains which are placed upon the trough walls; the excess of heat produced in operation, and the liability'of these walls to wear.

While I have shown and described one form of the invention, it will be understood that I do not wish to be limited thereto, as various changes may be made therein without departing from the spirit of the invention.

What 1 claim is:

1. In a machine of the'character described, a frame, a rotor turning in said frame, and a trough in which the rotor operates, the wall of said trough forming the working surface being separable from the frame, whereby such wal may be renewed, the frame and wall being constructed one with a groove and the other adapted to enter said groove.

In a machine of the character described, a frame, a rotor turning in said frame, and a. trough in which the rotor operates, the wall of said trough forming the working surface being separable from the frame, whereby such wall may be renewed, and the frame and wall being provided with means to prevent angular movement of said wall, said means comprising a flange arranged at an angle to the wall and engaging the frame.

3. In a machine of the character described, a frame, a rotor turning in said frame, and a trough in which the rotor operates, the wall of said trough forming the working surface being separable from the frame, whereby such wall may be renewed, and grooves on the frame receiving the ends of the wall, the grooves being of a depth to permit expansion of said wall.

l. A machine of the character described,

having a frame, a rotor, and a trough in which the rotor operates, the trough being separable from the frame, and spaced members contacting with the trough on its outer face.

5. A machine of the character described, having a frame, a rotor, and a trough in which the rotor operates, the trough being separable from the frame, and spaced members contacting with the trough on its outer face, said spaced members being longitudinally extended and arranged in a substanti'a'L ly circular series. 1

6. A machine of the character described, having a frame, a rotor in said frame, a separable trough'inwhich said rotor operates, means for supporting thetrough between its ends, said trough comprising a wall, and

means for'applying a cooling fluid to said trough, said trough being supported'so that the cooling fluid is applied directly to the outer surface of said wall.

7. A machine of the character described,

comprising a frame, a rotor in said'frame, a trough in which said rotor operates, said trough comprising a separable wall, and a supporting grid for said wall, the members of which are spaced apart so that the rear v of said wall is exposed.

' ing a substantially vertical flange engaging a part of the frame to prevent angular move ment of the wall.

9. A machine of the character described, comprising a frame, a rotor in said frame, a trough in which said rotor operates, said trough comprising a removable wall, means for supporting said trough between its ends and means for spraying cooling fluid directly against the outer surface of said wall.

10. A machine of the character described, comprising a frame the ends of which are separable and are formed with grooves, a trough entering said grooves, a supporting grid for said trough. and a rotor operating in said trough, the latter being removable by separating said end pieces.

11. A machine of the character described, comprising a frame the ends of which are separable and are formed with grooves, a trough entering said grooves, a supporting grid for said trough, and a rotor operating in said trough, the latter being removable by separating said end pieces. and said trough having a substantially vertical flange connected with the frame to resist angular movement of the trough.

12. A machine of the character described, comprising a frame the ends of which are separable and are-formed with grooves. a trough entering said grooves, a supporting grid for said trough, and a rotor operating in said trough, the latter being removable by separating said end pieces, and said trough having a substantially vertical flange connected with the frame to resist angular movement of the trough, a valve or gate for said machine and said vertical flange forming a contiguous wall to said valve or gate.

13. A machine for mixing rubber or the like, comprising a stationar frame, a pair of rotors rotatable in said rame, two partially cylindrical troughs in Which said rotors rotate and against the inner surface of which the material is pressed and worked under high pressure, said troughs being formed separately from said frame, and held in place therein against any undue movement, and means for supporting said troughs between their ends, said means being open to permit access of cooling Water or the like directly to the rear surfaces of the troughs.

In Witness whereof, I have hereunto signed my name.

FERNLEY H. BANBURY. 

